Hair clipper with improved on/off switch

ABSTRACT

A flat on/off switch for a small, elongated hand-held appliance such as a hair clipper is disclosed. The switch consists of four parts. A resilient contact member, a carrier for the contact member, a knob section and an elliptical plastic spring. The contact member and the carrier are riveted together, but none of the other parts of the switch are preassembled. The carrier is pivoted about an upstanding boss on the upper housing. A downwardly directed pin on the spring engages a curved surface of the carrier while an upwardly directed pin on the spring is inserted into a hole in the knob section.

United States Patent 1191 Houser HAIR CLIPPER WITH IMPROVED ON/OFF SWITCH [75] Inventor: John M. Houser, Milwaukee, Wis. [73] Assignee: Oster Corporation, Milwaukee, Wis. [22] Filed: Nov. 13, 1972 21 Appl. No 305,952

[52] U.S. Cl 200/157, 310/68 A, 310/71 [51] Int. Cl. I'I0lh 13/08 [58] Field of Search 200/157, 67 C, 153 LA, 200/676, 166 J, 153 W; 74/99 R, 106, 100 R;

1451 Nov. 5, 1974 3,328,542 6/1967 Andrews 200/157 UX 3,474,204 10/1969 Cork 200/166 .1 X 3,541,280 11/1970 Farrell 200/67 G X 57] ABSTRACT A flat on/off switch for a small, elongated hand-held appliance such as a hair clipper is disclosed. The switch consists of four parts. A resilient contact member, a carrier for the contact member, a knob section and an elliptical plastic spring. The contact member 56 R f C1 d and the carrier are riveted together, but none of the 1 e erences e other parts of the switch are preassembled. The car- UNITED STATES PATENTS rier is pivoted about an upstanding boss on the upper 2,441,924 5/1948 Steinback 200/67 C housing. A downwardly directed pin on the spring en- 2,5l2,499 6/1950 Loosen 200/157 UX gages a curved surface of the carrier while an up 5 33 39 2x32; 579? 200/ wardly directed pin on the spring is inserted into a mg er e a. 3,222,473 12/1965 Delhase 200/153 w ux hole m the knob 3,240,966 3/1966 Thompson 310/71 X 8 Claims, 14 Drawing Figures 2Z6 0 j a i r 225 fiATENIEunuv 5 mm 3. 846. 603

mm 1 or 3 i110 OFF 126 332 231 224 PATENTEDNUV 51914 SKEHMFZ! wm w $5 mm ww 3 E mww 8% 3 a g MN wk ms I? mm 3 R 8m fig w m mfl w w MW I mm m I WM Qfi r dmww m on. mm 5 g m W I If I h PM ii 4M 9% IIII m 1 6R Q H g &3 aw mw E m mm m m3 1 mm wm mm ww VV 3 N R Wm ww k Q3 wan mm HAIR CLIPPER WITH IMPROVED ON/OFF SWITCH BACKGROUND OF THE INVENTION The present invention relates to electric hair clippers and more specifically, to an electric hair clipper that is driven by an oscillating armature type of electric motor having an improved on/off switch. Several years ago, the assignee of the present invention introduced a hair clipper utilizing a vibratory oscillating armature type of electric motor which was especially designed for used by professional barbers. This previously introduced hair clipper of the assignee is described in US. Pat. No. 3,493,793, patented Feb. 3, 1970 on an application of Paul W. Niemela which was filed July 5, 1968. The present invention is described with reference to an embodiment which utilizes a motor that is similar to that of the Niemela patent, but it is not intended that the invention be limited solely thereto.

The hair clipper of the Niemela patent employed a vibratory motor that had a high power output per unit weight. Thus, the weight of a hair clipper could be reduced significantly by using this motor so as to relieve the fatigue of a barber who used the hair clipper relatively constantly during the working portion of his day. The hair clipper of the Niemela patent and the hair clipper of the described embodiment both employ armatures with a minimum mass and their armatures reverse direction with a minimum amount of noticeable housing vibration. This is also particularly important since acceptance of vibratory motor hair clippers has been limited in the past because of the presence of excessive vibration of the clipper housing. In addition, vibratory magnetic clippers were unpopular prior to the introduction of the clipper of the Niemela patent because they were sensitive to the fluctuation in the supply voltage or to change in the load. The vibratory motors of the Niemela patent and of the disclosed embodiment ofthe present invention herein are not inherently load sensitive as are the prior devices.

Despite the successful and highly satisfactory construction of the hair clipper of the Niemela patent, it has been found that several problems still existed with respect to the design of the hair clipper of that patent. In the hair clipper of the Niemela patent, the armature was pivoted for oscillating movement about a bearing pin which was secured to the lower housing of the clipper. On each side of the armature, a coil spring was compressed between the lower housing member and the nylon magnet supporting carrier of the armature. The housing had to be constructed so that a pair of U- shaped recesses or spring recesses were formed in it to receive the outer ends of the springs. The other ends of the springs were received by locating bosses on the nylon carrier. In order to dampen vibration noises associated with these springs, they were filled with a foam plastic material. This construction required that the housing be much wider than is optimum for the hand of the average user. The width of the housing made the clipper too bulky to be used comfortably by a user with an average or a small hand over a relatively long period of time.

The elongated hair clipper of the present invention by contrast is extremely narrow and thin and it is, therefore, very easily gripped by even the user with very small hands. The major reasons for this improved shape being that torsion springs are employed in the hair clipper of the present invention which are coiled around the vertical axis of the bearing pin and the use of a new and improved very flat on/off switch. Thus, the elongated hair clipper can be made narrower without increasing its vertical dimension. ln addition, with the use of torsion springs, much heavier springs can be employed, and thus, the problem of occasional spring breakage which occurred with the smaller coil springs of the clipper of the Niemela patent is eliminated.

The torsion springs also serve to hold the armature in place on the bearing pin. Because of this, a separate metal field locating and support member is not re quired in the hair clipper of the described embodiment as it is in the hair clipper of the Niemela patent. In the clipper of the present invention, the field is located by plastic abutments which are integrally formed on the housing and by a resilient bushing which is compressed when the upper and lower housing members are secured together. The bushing forces the mating cut-out surfaces on the field structure forward thereby forcing abutting members on the field structure against the locating abutments on the housing.

In the hair clipper of the Niemela patent, blade drive was achieved by means of an extension of the armature which drove the upper blade or the cutter by contact of the armature extension and the cutter along a line. The necessary pressure was maintained by an elongated biasing spring that was screwed into the lower housing of the cutter of the clipper. The biasing spring had a plastic block on its outer end which was inserted into a groove in the cutter so as to force the cutter against the comb.

The drive mechanism described in the previous paragraph has a number of disadvantages. First of all, since the armature extension makes contact with the cutter along a line, excessive wear of the cutter and of the armature may occur. In addition, the biasing spring may be subjected to bending or twisting with respect to the armature which could result in improper or uneven pressure upon the cutter which in turn would result in impaired cutting efficiency and increased load on the armature.

The previously mentioned Niemela patent employed a horizontal slideable knob which projected through the side of the housing and was connected to the on/off switch. The switch was mounted at the rear of a metal frame which located the field and was connected to the knob through an elongated extension arm. This arrangement was satisfactory from an operating standpoint, but it caused the thickness of the motor clipper to be greater than is desirable for a hand-held clipper, as previously mentioned.

In order to reduce the dimension of the hair clipper in the vertical direction, the present hair clipper employs a new and improved switch of a very flat construction. The switch of the described embodiment is useful for hand-held appliances and tools other than hair clippers. The movable part of the switch has only four parts and the only preassembly operation that is required for this assembly is the riveting of a spring contact member to a carrier member. Thus, the cost of the movable assembly of this switch is relatively low. The switch is designed so as to operate with an overcenter action when the horizontal slideable knob transmits a force through an elliptically shaped plastic spring to the carrier, thereby causing the carrier to pivot toward or away from a pair of stationary contacts on the field structure of the motor.

It is an object of the present invention to provide a very flat on/off switch for portable motorized devices, including hair clippers and the like, which consists of a movable contact assembly and a fixed contact assembly.

It is an additional object of the present invention to provide a new and improved on/off switch for a motor operated device having a field structure with a bobbin which supports a plurality of stationary contacts for making connection to the field coil and to the power source and a movable assembly which preferably is formed of slideable knob section, a carrier which supports a movable contact member that engages the stationary contacts of the field structure and a resilient spring member which couples the knob section to the carrier.

It is another object of the present invention to provide an on/off switch with a movable assembly which is constructed witha minimum of preassembled parts,

the'only preassembled part being the carrier which consists of a movable contact member and a carrier plate to which the contact member is secured, wherein the movable assembly comprises a very flat configuration and the movable assembly functions to move the movable contact member into and out of engagement with a plurality of stationary contact members when a knob slides back and forth in the housing of the device that utilizes the switch. I

It is a further object of the present invention to provide an on/off switch for energizing an electric motor that is housed in a portable deviceby means of a movable contact member which bridges a pair of stationary contact members that are secured to the bobbin on which the field coil for the motor is wound, wherein the movable contact member is part of a movable assembly which comprises a knob section that moves in the housing of the device, a carrier which supports the movable contact member and which is pivotally mounted with respect to the housing, and a spring member, preferably of a closed elliptical configuration, which has oppositely directed pins extending therefrom such that one of the pins is coupled to the knob section and the other pin is coupled to the carrier whereby pivotal motion of the carrier, preferably of the over-center type, is obtained by operation of the knob by the user of the de- VICC.

Additional advantages and objects of the present invention will be apparent to those skilled in the art from this document.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the hair clipper of the present invention with the upper blade or cutter removed;

FIG. 2 is a cross-sectional view of the hair clipper taken along the line 2-2 of FIG. 1;

FIG. 3 is a plan view looking into the upper housing of the hair clipper with the lower housing removed, but with other parts of the clipper in place;'

FIG. 4 is a side view of the hair clipper motor with the torsion return bias spring in place on the armature;

FIG. 5 is a side view of the motor field structure and its associated electrical contacts;

FIG. 6 is an exploded perspective view of theon/off switch with the lower portion of the switch, when assembled, being shown ,at the top of the figure;

FIG. 7 is a top partial cut-away view of the upper housing of the hair clipper showing the on/off switch in the off position;

FIG. 8 is a partial cut-away view of the upper housing of the hair clipper showing the on/off switch in the on position,

FIG. 9 is a cross-sectional view of the field structure taken along the lines 9-9 of FIG. 5;

FIG. 10 is a cross-sectional view of the field structure taken along the lines l0-10 of FIG. 9;

FIG. 11 is a side and partial cross-sectional view of the bobbin of the field structure;

FIG. 12 is a side view of the armature of the clipper motor;

FIG. 13 is a top view of the armature 0f the clipper motor; and

FIG. 14 is a front viewof the motor field structure which shows the salient magnetic poles of the field.

TECHNICAL DESCRIPTION OF THE INVENTION With reference to the drawings, there is shown in FIG. 1 a hair clipper designated generally by reference numeral 20. The hair clipper 20 includes a housing 22 which is made of an upper housing member 24 and a lower housing member 26. The upper and lower housing members are secured together in abutting relationship by screws 28, 30 to form a motor enclosure 32, as shown in FIG. 2. The housing 22 is preferably formed of a plastic such as phenolic.

A removable blade set 34 is received on the front end of the clipper. The blade set 34 consists of a lower blade or comb 36 and an upper blade or cutter 38 which is pressed into shearing engagement with the comb 36, by a blade drive assembly 40. The comb 36 is secured to the lower housing member 26 by a screw 42 which passes through an opening 44 in the lower portion of the comb 36 and then into a threaded channel 46. There is a small amount of clearance between the screw 42 and the size of the opening 44 so that ad-- justment of the comb 36 may be easily made in order to achieve proper alignment of the comb 36 and the cutter 38. The comb 36 and the cutter 38 are provided with teeth which have abutting outer edges in the conventional manner so that relative movement between the cutter 38 and the comb 36 will result in the desired cutting action of the hair.

The cutter 38 is provided with a plastic snap-fit drive shoe 48 which is part of the blade drive assembly 40. The drive shoe 48 has projecting cars 50 that are constructed to extend through slots 38a in the cutter when the ears 50 are pressed towards each other. When the pressure is released on the ears 50, they are forced apart by the natural resiliency of the plastic against the outer edges of the slot 38a so as to lock the drive shoe 48 onto the cutter 38. The drive shoe 48, which is best shown in FIG. 3 where the cutter 38 has been removed, is provided with the snap-fit ears 50 so that the cutter 38 may be removed and replaced by a new blade when it is dull. The cutter 38 is made of metal and is relatively thin and lightweight, and with the ease of assembly that .is provided by the present invention, it becomes more economical and convenient to replace the cutter 38 when it is dull rather than to resharpen it.

The rear end of the drive shoe 48,. which faces towards the motor enclosure 32 is formed in the shape of a trapezoidal channel 52. The trapezoidal channel 52 is open at its bottom and has a top surface 59 and side surfaces 58, 60. Force supplied to the drive shoe 48 through the side surfaces 58, 60 of channel 52 presses the cutter 38 and the comb 36 together and drives a guide surface 54 at the front end of the drive shoe 48 against a downwardly depending mating guide surface 56 on the upper housing member 24. The guide surface 56 is substantially at a right angle with respect to the elongated planer surface 38b of the cutter 38. At this angle, the optimum normal force between the cutter 38 and the comb 36 and the optimum normal force between the guide surfaces 54, 56 are obtained. The manner in which the required driving force is transmitted to the side surfaces 58, 60 of the drive shoe 48 by the remaining elements of the drive assembly 40 is described later herein.

The required mechanical power for the hair clipper is provided by the electrical motor 62 which includes a field or stator 64 and an oscillating armature 66. The armature 66 is supported for oscillating movement by means of a steel bearing pin 68 which has an upper end 68a of reduced diameter that is molded into the housing member 24. An oil impregnated bushing 70 is integrally formed with the armature 66 so as to reduce the friction between the armature 66 and the bearing pin 68. The rear portion of the armature 66 consists of a rigid insulating frame or carrier 72, which is preferably constructed of nylon and into which permanent magnets 74, 76 are integrally molded.

A permanent magnet 78, which is preferably formed of a ferrite ceramic material is positioned in the carrier 72 between the pole pieces 74, 76. The pole pieces 74, 76 are elongated members that are formed of a suitable, magnetically permeable material, which may be sintered iron. The pole pieces 74, 76 have at their outer ends a pair of salient pole faces 74a, 74b and 76a, 76b, respectively. The permanent magnet 78 is polarized so that the pole pieces 74, 76 are magnetized to the opposite polarities. As a consequence, the salient pole faces 74a, 74b of the pole 74 will be magnetized to the opposite polarity of the salient pole faces 76a, 76b of the pole 76. Thus, when the pole faces 74a, 74b are of a North pole, the pole faces 76a, 76b will be a South pole; and when the pole faces 74a, 74b are of a South pole, the pole faces 76a, 76b will be of a North pole.

The front end of the carrier 72 of the armature 66 has a steel drive pin 80 which has a rear portion of a reduced diameter 80a that is integrally molded into the forward section of the armature 66. The drive pin 80 passes through a rectangular boss 67 on the forward section of the armature 66. A foam pad 68, which is preferably formed of polyether, surrounds the boss 67 to prevent hair clippings from entering the motor enclosure 32. A drive bearing 84 which is preferably formed of plastic and which has a hollow cylindrical bearing surface 84a that receives the drive pin 80 and ball socket section 84b transmits driving force to drive socket 86. A coil spring 82 surrounds the hollow cylindrical bearing section 840 and it is compressed around this section between the surface 67a of the boss 67 and the surface 840 of the drive bearing 84. The ball socket section 84b of the drive bearing 84 transmits the forwardly directed force to the plastic drive socket 86, the

concave spherical recess 86a which receives the ball socket section 84b in mating relationship.

The plastic drive socket 86 has a front surface 92 and a pair of side surfaces 88, 90 which form a trapezoid that mates with the trapezoidal channel 52 that is formed in the drive shoe 48. The side surfaces 88, 90 of the drive socket 86 abut against the side surfaces 58, 60 of the drive shoe 48 so as to impart a substantially uniform force to the drive shoe 48 along a relatively large surface area. By imparting the drive force along a relatively wide surface area a minimum of wear is insured. in order to prevent the binding of the socket 86 and the drive shoe 48, space is provided between the forward surface 92 of the drive socket 86 and the rear surface 59 of the trapezoidal channel 52 of the drive shoe 48. Although the drive shoe 48 itself could be formed with the corresponding spherical recess for receiving the ball socket section 84b. it is preferred that a separate drive member, such as the drive socket 86, be provided so that tolerances in the construction of the blade drive assembly may be increased. The drive socket 86 has a hole 860 in the spherical recesses 86b which prevents compression of air between the ball socket 84b and the recess 86b which would reduce the effectiveness of the blade drive mechanism.

In operation, the armature 66 is biased to a central position by means of a pair of torsion springs 94, 96 which surround a downwardly depending boss 98 that is formed on the upper housing 24 and the downwardly depending portion 70b of the bushing 70. The carrier section 72 of the armature 66 has a pair of apertures therein, 100, 102 for receiving the bent outer ends 104, 105, respectively, of the torsion springs 94, 96. Slightly sloped spring channels 106, 107 are formed around the upper portion 70a and on the uppermost part of the lower portion 70b of the bearing 70. Sloped spring support bearings 75, 77 are also formed in the upper and lower housing members 24, 26, as shown in FIG. 2. The torsion springs 94, 96 are placed in the spring channels 106, 107, respectively, and are coiled around the vertical axis of the drive pin 80. A pair of cut-away landings 109, 111 are provided at the outer edge of the spring channels 106, 107, respectively, below the level of the upper and lower exterior surfaces 113 and 115 of the carrier 72. The ends 117, 119 of the torsion springs 94, 96 which are not inserted into the apertures 100, 102 are then placed in the landings 109, 111 so that they extend outwardly until they abut against the respective one of the shoulders 121, 123 which are formed integrally with the lower housing member 26. Thus, the springs 94, 96 are able to return the armature 72 to its center position by means of the torsion spring effect that is exhibited by the springs 94, 96 due to the force that is applied between the outer ends 117, 119 of the springs 94, 96 and the corresponding shoulder portions 121, 123 of the housing 22.

By employing torsion springs that are wound about the vertical axis of the bearing pin 68 instead of horizontally oriented coiled springs, such as those employed in the clipper of the previously mentioned Niemela patent, a very slim and compact hair clipper may be constructed. In addition, by using torsion springs much larger springs can be used and, therefore, the possibility of spring breakage is reduced. The torsion springs 94, 96 are preferably formed of tin plated music wire or the like.

The field 64 for the hair clipper consists of core 114 which is formed of a stack of E-shaped laminations 118 that are made of magnetically permeable material which are retained together and are secured to a plastic supporting bobbin 116 by means of rivets 20. The E- shaped core 114 has a pair of outer legs 120, 122, and a central leg 124. The central leg 124 is substantially thicker than the outer legs 120, 122 and it terminates in a pair of salient poles 124a, l24b. The outer legs 120, 122 of the core 114 terminate in a salient pole pairs 120a, 122a, respectively. Surrounding the central leg 124 of the core 114 is a field coil 126 which is best shown in FIG. 5. The bobbin 116 has a hollow cylindrical center around which the windings of the coil 126 are wound. The coil 126 is formed of magnetic wire having a conventional suitable insulation thereon. The inside surfaces of the outer legs 120, 122 are further insulated from the coil 126 by a pair of fibre insulators 126, 127 which are inserted between the legs 120, 122 and the outside of the coil 126 (FIG. 3).

When the coil 126 is energized by electrical current flowing in either direction, it will induce magnetic flux in the core 114 which will cause the salient pole faces 124a, 12411 of the central leg 124 to be magnetized to one polarity, while the salient pole faces 120a, 122a of the outer legs 120, 122, respectively, will be magnetized to the opposite polarity. By means of the interaction that occurs between the salient poles 120a, 122a, 124a and 124b of the core 114 and the salient poles 74a, 74b, 76a and 76b of the armature 66, the desired vibratory action of the motor is obtained. A more complete description of the operation of a motor that is employed in the present invention may be obtainedby reference to the aforementioned Niemela Patent. However, it should be appreciated that the present invention is not limited to the specific type of motor shown in the Niemela patent.

The bobbin 116 on which the coil 126 is wound is formed with a pair of end panels 130, 132 which extend on opposite sides of the central section 128 so as to form a reel for the coil 126. In addition, however, both the front end panel 130 and the rear end panel 132 are provided with a pair of grooves which are used to receive a pair of electrical contact members so as to provide the required electrical connection to the field coil 126 and to the power source. For example, the slots 134, 136 are provided in the front end panel 130 for receiving the electrically conducted connectors 138, 140, respectively. The connectors 138, 140 extend downwardly into the slots 134, 136 along substantially the entire length of the rear end panel 132 and down beyond a forwardly extending ledge 142 of the rear end panel 132. The lower ends of the connectors 138, 140 are then outwardly bent and end in terminals 138a, 1400. The forward end of the field coil 126 is brought out and connected to the terminal 140a while the jumper wire 144, which is coupled to the power source, is connected to the terminal 138a.

A pair of slots 146, 148 are also formed in the rear end panel 132 of the bobbin 116 for receiving the connectors 150, 152. The connectors, 150, 152 extend downwardly along the rear end panel 130 for a major portion of its length. The lower end of the connectors 150, 152 are bent outwardly and they end in terminals 150a, 152a (FIG. 3). The rear end of the field coil 126 is brought out and is connected to the terminal 150a, and the jumper wire 144, which is also connected to the terminal 138a, is connected to terminal 152a. The terminals 150a, 152a are interconnected with the power cord 154 through a pair of removable female connectors 156, 158 which receive the male terminals 150a, 152a, respectively.

Input power is supplied to the motor 62 the hair clipper through the power cord 154 which passes into the clipper 20 through an aperture 156 in the rear face 158 of the housing 22. A flexible strain relief bushing 160 is secured around the power cord 154 at its end where it passes through the aperture 156. The strain relief bushing 160 has a forward rectangular section 160a and a ring-like section 160b which is separated from section 160a sufficiently to form an intermediate groove 160a that mates with a corresponding pair of ribs (not shown) formed on the upper and lower housing members 24, 26. This groove and rib thereby holds the bushing 160 in place in the housing 22.

In order that the clipper may be hung on a nail or hook when it is not in use, a bail 162, is preferably formed out of stainless steel, is also provided at the rear face of the clipper 20. The bail 162 is bent so as to act as a spring and the outer ends 162a, 162b of the bail 162 are bent upwardly so as to extend into the holes 164, 165 in the upper housing member 124, thereby securing the bail 162 to the housing 22.

One desirable feature of the hair clipper of the described embodiment is that the field 64 is held in place in the housing of the clipper without the necessity of coupling any external securing means to the field 64. Screws 28, 30 are screwed into the threaded boss 166 at the rear of the upper housing 24 and into the threaded lower end 68a of the bearing pin 68, respectively, to hold the upper and lower housing members 24, 26 together. The lower housing member 26 has an upwardly projecting cylindrical boss 168 through which the screw 28 also projects. The ledge 154 of the bobbin 116 is formed with two legs 154a, 154b, while the forward portion of the ledge 154 and the core 114 both have a semicircular cutout section 164 so that the legs 154a, 1541) of the ledge 154 extend around the lower boss 168. A resilient, compressible cylindrical bushing 170 which is made of neoprene, or other suitable material, is positioned between the bosses 166, 168 and positioned so that the semicircular cutout portion 164 of the edge 114a of the core 114 conforms to the cylindrical outer surface of the bushing 170, as best shown in FIG. 2. The insulating member 170 is compressed between the bosses 166 and 168 when the screws 28, 30 are screwed into their respective bosses and as the bushing 170 is compressed, it presses forward against the edge 114a of the core 114 to urge the field 64 forward. As the field 64 is pressed forward by the compressed bushing 170, the abutments 184, 186 on the outer legs 120, 122 of the laminations of the Core 114 are pressed into contact with abutments 188, that are integrally formed on the upper housing member 24. When the abutments 184, 186 of the field 64 are pressed into contact with the abutments 188, 190, respectively, of the housing 22 and the rear edge 114a of the core 114 is wedged against the compressed bushing 170, the field 74 is secured firmly in place in the housing.

A pair of resilient foam pad strips 172, 174 are cemented to the bottom of the core 114. The foam pad strips 172, 174'are compressed against the integrally formed runners 176 of the lower housing member 26 when the housing is secured together. These strips 172, 174 are also bent up as the upwardly forward portion of the core 114 so as to abut against the upwardly projecting abutment members 180, 182 of the lower housing member 26. The foam strips 172, 174 are then flattened out when the housing is assembled to take up any looseness that might otherwise exist between the field 64 and the housing 22 to cushion movement of the field 64.

The described construction for positioning the field in its proper place eliminates the need for special mounting frames and also the necessity of putting holes in the core structure. In the motor of the described embodiment, the core laminations 114 are preferably very thin in order to minimize core losses, and if holes were drilled in the laminations and mounting screws were inserted in these holes the magnetic properties of the core would be substantially deteriorated.

The on/off switch 191 of the hair clipper of the described embodiment is very flat, which allows for a reduction in the exterior dimensions of the housing. The on/off switch 191 is very simple to assemble since only one pre-assembly operation is required for the movable assembly 192 of the switch. As will be apparent, the construction details on the movable assembly 192 of the on/off switch 191 are best shown in the exploded perspective view of FIG. 6. In FIG. 6, the bottom of the movable assembly 192 appears at the uppermost portion of the figure while the upper housing 26 is at the lower end of the figure. The connectors 138, 140 which are inserted into slots 134, 136 of the front end panel 130 of the bobbin 116 form the stationary contact members for the on/off switch 191.

The contact members 138, 140 have punched tab sections 138k, 14% located just above the ledge 142. The punched tab sections 138b, 140b hold the contacts 138, 140 on the bobbin 116.

The movable assembly 192 consists of three parts which are assembled together. The three parts are the carrier 196, the closed spring 200 and the knob section 202. The carrier 196 of the movable assembly 192 consists of the spring contact member 194 and the carrier plate 195 to which the spring contact member 194 is secured by means of a rivet 198. The carrier plate 195 may be formed of any suitable rigid insulating material. A hole 204 is provided at the forward end of the carrier plate 195 so that a projecting pin 206 which is integrally formed in the upper housing member 24 passes through the hole in the vertical direction to allow for pivoting of the carrier plate 195 about the pin 206. A slotted channel 208 which is formed in the inner edge 210 of the carrier plate 195 has a curved segment 212 at its inner end.

The spring 200 is preferably formed of a closed resilient plastic ring which is preferably of an elliptical shape, however the resilient spring form of any suitable material may be used and it is not necessary that the spring be of elliptical shape. It has a pair of diametrically opposite integrally formed pins which project in opposite directions from its outer periphery. One of the pins is a relatively long pin 213 which extends into the curved segment 212 of the carrier plate 195 couples the carrier plate 195 to the spring 200. The other pin 214 is a shorter pin which projects through a hole 216 which is provided on the horizontally extending plate 218 which is integrally formed on the knob section 202.

r in the vicinity of the opening 224 which receives a corresponding rib that is formed on the lower housing member 26 and a second slot 228 in the vicinity of the opening 224 which fits over the recessed segment 230 of the upper housing member 24. Thus, the rib which is formed in the lower housing member 26 will ride in the slot 225 and the recessed segment 230 of the upper housing member 24 will ride in the slot 228 when the knob 232 is pushed back and forth along the elongated direction of the hair clipper.

The operation of the switch mechanism 204 is best shown by reference to FIGS. 7 and 8. In order to turn the hair clipper on, an electrical connection must be made between the connectors 138, 140. The contact 140 is directly wired to one end of the field coil 126 through the terminal 140a while the contact 138 is wired through the jumper lead 144 which is connected to the terminal 138a to one side of the input power source via the power cord 154.

The rear end of the carrier plate 195 has an angular abutment 220 which extends outwardly therefrom. During the movement of the knob 232 of the knob section 202 towards the rear of the clipper, the abutment 220 slides on the elongated, integrally formed runner 227 of the upper housing 24 towards the post 222 of the upper housing member 24. When the switch is in the off position, the outwardly extending abutment 220 of thecarrier plate 195 will be in contact with the post 222. Further movement of the switch knob section 202 and the abutment 220 is thus prevented and the contact or bridging member 194 is out of engagement with the connectors 138, 140. The position of the resilient contact 194 with respect to the stationary connectors 138, 140 when the switch 191 is in the off position is shown in FIG. 7.

When the knob 232 is pushed toward the front end i of the clipper 20 to which the cord 154 is connected the switch 191 is switched to its on position and the position of the contact 194 with respect to the stationary connectors 138, is shown in FIG. 8. As the carrier 196 is moved backward, the two arms 236, 238 of the contact member 194 that extend forward of the flat section 240 come into contact with the connectors 138, 140. Once electrical connection is made in this manner, the field coil 126 is supplied with electrical current through the power cord 154 and the motor 62 is thereby set into vibratory motion.

As shown in FIGS. 7 and 8, the pin 213 is positioned in the curved segment 212 both when the switch 191 is in its off position and when it is in its on position. When the carrier plate 195 pivots relative to the knob plate 218 as the knob 232 is moved, the spring 200 yields somewhat and rotates in a counter-clockwise direction when the knob 232 is moved forward toward the on position and in a clockwise direction when the switch is moved backward toward the off position.

The extension 242 of the plate 218 which projects outwardly from the bottom of the slide member 226 of the knob section 202 has another function in addition to being part of the structure that couples the knob section 202 to the carrier 196.

While there has been illustrated and described a particular embodiment of the present invention, it will be understood that changes and modifications may occur to those skilled in the art, and it is, therefore, contemplated by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the present invention.

What is claimed.

1. An electric appliance comprising a housing enclos ing a motor which is drivingly connected to an implement mounted exteriorly of said housing, a power cord connected to said housing, a switch for electrically connecting said motor to said power cord including a manually operable member slidably in the wall of said housing and having a knob outside of said housing and an operating portion within said housing, spaced fixed contacts supported by insulating means on said motor, movable contact bridging means supported on a carrier pivotally mounted on the inside wall of said housing, over center spring means pivotally connected to said carrier and to said operating portion to urge said movable contact bridging means into or out of engagement with said fixed contacts when said manually operable member is moved to the limit of its sliding movement in either direction, said housing including stop means to limit pivotal movement of said carrier when said over center spring means is urging said contact bridging means out of engagement with said fixed contacts, said over center spring mechanism comprises a plastic ring having integral parallel projections extending in opposite directions from diametrically opposed portions of said ring, said projections being received in openings in said carrier and said operating portion.

2. An electrical appliance comprising a housing and an electrical motor in said housing with a field means including a bobbin, magnetic laminations supported by carrier on said housing, coupling means for interconnecting said carrier and said coupling portion of said knob section whereby said carrier pivots to engage said movable contacts with said pair of stationary contacts when said knob in its first position and said movable contacts are disengaged from said pair of stationary contacts when said knob is in its second position.

3. An electrical appliance comprising a housing enclosing a motor having a field with a coil bobbin, a switch for controlling energization of said motor, said housing including housing members which abutt along a common plane, a slot formed in said ho'usingbetween said housing members, a manually operable switch control slidably mounted in said slot and guided for movement by the portions of said housing members defining or adjacent to said slot, said motor including fixed contacts mounted on said coil bobbin, a contact supporting member pivotally supported on one of said housing members and having movable contacts supported thereon, said contact supporting member being pivotal between a first position with said movable contacts in engagement with said fixed contacts to connect said coil to a source of electrical power and a second position in which said movable contacts are disengaged from said fixed contacts, an overcenter spring mechanism pivotally connected to said contact supporting member and said switch control, said mechanism urging said supporting member to either said first or second position in response to sliding movement of said control.

4. The electrical appliance as set forth in claim 3 wherein said housing has stop means thereon and said supporting member has one or more edges which are in engagement with said stop means when said supporting member is in said second position.

5. The electrical appliance as set forth in claim 3 wherein said mechanism is a resilient means having a closed configuration, said control having a first opening therein, said supporting member having a second opening therein, a first pivot member is located on the periphery of said mechanism extending into said first opening and a second pivot member is located on the periphery of said resilient means diametrically opposite to said first member and extending into said second opening.

6. An electrical switch as set forth in claim 3 wherein said movable contacts on said supporting member comprise a plurality of spring arms, each of which contact one of said fixed contacts when said supproting member is in said first position.

7. The combination of claim 3 wherein said bobbin includes spaced end walls, said fixed contacts being L- shaped members mounted on one of said end walls, each L-shaped member having one leg extending in the plane of said one end wall, each said one leg being parallel to the other, said field including a coil wound on said bobbin and having a terminal end connected to the other leg of one of said L-shaped members, a lead to a power source connected to the other leg of the other one of said L-shaped members, said movable contacts engaging the L-shaped members near the free end of each said one leg to electrically interconnect said L- shaped members.

8. The combination of claim 3 wherein said bobbin includes spaced end walls, said fixed contacts being L- shaped members mounted on one of said end walls, each L-shaped member having one leg extending in the plane of said one end wall and another leg extending outwardly from said one end wall, said movable contacts engaging each of the fixed contacts at the end of said one leg remote from said other leg. 

1. An electric appliance comprising a housing enclosing a motor which is drivingly connected to an implement mounted exteriorly of said housing, a power cord connected to said housing, a switch for electrically connecting said motor to said power cord including a manually operable member slidably in the wall of said housing and having a knob outside of said housing and an operating portion within said housing, spaced fixed contacts supported by insulating means on said motor, movable contact bridging means supported on a carrier pivotally mounted on the inside wall of said housing, over center spring means pivotally connected to said carrier and to said operating portion to urge said movable contact bridging means into or out of engagement with said fixed contacts when said manually operable member is moved to the limit of its sliding movement in either direction, said housing including stop means to limit pivotal movement of said carrier when said over center spring means is urging said contact bridging means out of engagement with said fixed contacts, said over center spring mechanism comprises a plastic ring having integral parallel projections extending in opposite directions from diametrically opposed portions of said ring, said projections being received in openings in said carrier and said operating portion.
 2. An electrical appliance comprising a housing and an electrical motor in said housing with a field means including a bobbin, magnetic laminations supported by said bobbin and a field coil wound on said bobbin, a switch including a pair of stationary contacts secured to said bobbin and a movable contact assembly positioned in and supported on said housing, said movable contact assembly comprising a knob section having a knob and coupling portion, said housing having walls mounting said knob section extending through said walls for slideable back and forth movement between a first position and a second position, said movable contact assembly including a carrier having movable contacts thereon, means for pivotally supporting said carrier on said housing, coupling means for interconnecting said carrier and said coupling portion of said knob section whereby said carrier pivots to engage said movable contacts with said pair of stationary contacts when said knob in its first position and said movable contacts are disengaged from said pair of stationary contacts when said knob is in its second position.
 3. An electrical appliance comprising a housing enclosing a motor having a field with a coil bobbin, a switch for controlling energization of said motor, said housing including housing members which abutt along a common plane, a slot formed in said housing between said housing members, a manually operable switch control slidably mounted in said slot and guided for movement by the portions of said housing members defining or adjacent to said slot, said motor including fixed contacts mounted on said coil bobbin, a contact supporting member pivotally supported on one of said housing members and having movable contacts supported thereon, said contact supporting member being pivotal between a first position with said movable contacts in engagement with said fixed contacts to connect said coil to a source of electrical power and a second position in which said movable contacts are disengaged from said fixed contacts, an overcenter spring mechanism pivotally connected to said contact supporting member and said switch control, said mechanism urging said supporting member to either said first or second position in response to sliding movement of said control.
 4. The electrical appliance as set forth in claim 3 wherein said housing has stop means thereon and said supporting member has one or more edges which are in engagement with said stop means when said supporting member is in said second position.
 5. The electrical appliance as set forth in claim 3 wherein said mechanism is a resilient means having a closed configuration, said control having a first opening therein, said supporting member having a second opening therein, a first pivot member is located on the periphery of said mechanism extending into said first opening and a second pivot member is located on the periphery of said resilient means diametrically opposite to said first member and extending into said second opening.
 6. An electrical switch as set forth in claim 3 wherein said movable contacts on said supporting member comprise a plurality of spring arms, each of which contact one of said fixed contacts when said supproting member is in said first position.
 7. The combination of claim 3 wherein said bobbin includes spaced end walls, said fixed contacts being L-shaped members mounted on one of said end walls, each L-shaped member having one leg extending in the plane of said one end wall, each said one leg being parallel to the other, said field including a coil wound on said bobbin and having a terminal end connected to the other leg of one of said L-shaped members, a lead to a power source connected to the other leg of the other one of said L-shaped members, said movable contacts engaging the L-shaped members near the free end of each said one leg to electrically interconnect said L-shaped members.
 8. The combination of claim 3 wherein said bobbin includes spaced end walls, said fixed contacts being L-shaped members mounted on one of said end walls, each L-shaped member having one leg extending in the plane of said one end wall and another leg extending outwardly from said one end wall, said movable contacts engaging each of the fixed contacts at the end of said one leg remote from said other leg. 